NH₄Fe^IIH(SO₄)₂·2H₂O

The structure of the title compound, ammonium iron(II) hydrogen bis(sulfate) dihydrate, NH₄FeH(SO₄)₂·2H₂O, is isotypic with three similar kröhnkite-type structures of type E. The Fe²⁺ cation is surrounded by two water mol­ecules and four partially protonated sulfate anions. The structure is completed by ammonium ions. The Fe and the N atom are located on centres of inversion.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](S-O) = 0.001 Å
• H-atom completeness 89%
• R factor = 0.018
• wR factor = 0.049
• Data-to-parameter ratio = 10.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)...          ?
PLAT354_ALERT_3_C Short   O-H Bond (0.82A)   O5     -   H5A    ...       0.71 Ang.

Alert level G
FORMU01_ALERT_2_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and the formula from the _atom_site* data.
            Atom count from _chemical_formula_sum:H9 Fe1 N1 O10 S2
            Atom count from the _atom_site data:  H8 Fe1 N1 O10 S2
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional?
           From the CIF: _cell_formula_units_Z    1
           From the CIF: _chemical_formula_sum  Fe H9 N O10 S2
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           Fe         1.00      1.00    0.00
           H          9.00      8.00    1.00
           N          1.00      1.00    0.00
           O         10.00     10.00    0.00
           S          2.00      2.00    0.00

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97.

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Crystal data

FeH9NO10S2	Z = 1
Mr = 303.05	F(000) = 154
Triclinic, P1	Dx = 2.347 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.5955 (9) Å	Cell parameters from 6924 reflections
b = 5.8420 (12) Å	θ = 3.6–27.4°
c = 8.3811 (16) Å	µ = 2.29 mm^−1
α = 103.678 (15)°	T = 100 K
β = 98.069 (16)°	Needle, colourless
γ = 95.638 (16)°	0.47 × 0.22 × 0.13 mm
V = 214.43 (8) Å^3

Data collection

STOE IPDS II two-circle diffractometer	980 independent reflections
Radiation source: fine-focus sealed tube	922 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
ω scans	θmax = 27.6°, θmin = 3.9°
Absorption correction: multi-scan (MULABS; Spek, 2003; Blessing, 1995)	h = −5→5
Tmin = 0.405, Tmax = 0.740	k = −7→7
3969 measured reflections	l = −10→10

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.018	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.049	w = 1/[σ^2(Fo^2) + (0.0271P)^2 + 0.0862P] where P = (Fo^2 + 2Fc^2)/3
S = 1.12	(Δ/σ)max < 0.001
980 reflections	Δρmax = 0.44 e Å^−3
92 parameters	Δρmin = −0.36 e Å^−3
4 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.148 (9)

Special details

Experimental. ;

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Fe	0.0000	0.0000	0.0000	0.01102 (12)
O5	0.1993 (3)	−0.2180 (2)	0.14161 (14)	0.0145 (2)
H5A	0.111 (6)	−0.311 (4)	0.160 (3)	0.025 (6)*
H5B	0.344 (6)	−0.270 (5)	0.126 (3)	0.029 (6)*
S	−0.60037 (7)	−0.31653 (6)	−0.23937 (4)	0.01068 (12)
O1	−0.4994 (3)	−0.3020 (2)	−0.40179 (13)	0.0200 (3)
O2	−0.3409 (2)	−0.28480 (19)	−0.10850 (13)	0.0154 (2)
O3	−0.7726 (2)	−0.54790 (19)	−0.26264 (13)	0.0171 (2)
O4	−0.7750 (2)	−0.11876 (19)	−0.20058 (13)	0.0142 (2)
N1	0.0000	0.0000	−0.5000	0.0170 (4)
H1A	−0.062 (10)	−0.145 (4)	−0.572 (5)	0.026 (11)*	0.50
H1B	−0.121 (10)	0.113 (7)	−0.504 (8)	0.038 (14)*	0.50
H1C	−0.150 (7)	−0.068 (8)	−0.460 (5)	0.025 (11)*	0.50
H1D	−0.097 (10)	0.030 (10)	−0.593 (4)	0.031 (12)*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe	0.01036 (17)	0.01036 (16)	0.01227 (16)	0.00139 (10)	0.00108 (10)	0.00323 (10)
O5	0.0122 (5)	0.0139 (5)	0.0204 (5)	0.0032 (4)	0.0047 (4)	0.0087 (4)
S	0.01309 (19)	0.00969 (18)	0.00858 (18)	−0.00021 (12)	0.00203 (12)	0.00158 (12)
O1	0.0311 (6)	0.0155 (5)	0.0123 (5)	−0.0046 (4)	0.0117 (4)	−0.0001 (4)
O2	0.0121 (5)	0.0144 (5)	0.0195 (5)	0.0012 (4)	−0.0003 (4)	0.0058 (4)
O3	0.0216 (6)	0.0125 (5)	0.0153 (5)	−0.0044 (4)	0.0061 (4)	0.0005 (4)
O4	0.0135 (5)	0.0159 (5)	0.0156 (5)	0.0052 (4)	0.0041 (4)	0.0065 (4)
N1	0.0214 (9)	0.0133 (8)	0.0139 (8)	−0.0001 (7)	−0.0025 (7)	0.0034 (7)

Geometric parameters (Å, º)

Fe—O2^i	2.1029 (11)	S—O2	1.4670 (11)
Fe—O2	2.1029 (11)	S—O4	1.4704 (11)
Fe—O4^ii	2.1105 (11)	S—O1	1.5164 (11)
Fe—O4^iii	2.1105 (11)	O4—Fe^iv	2.1105 (11)
Fe—O5^i	2.1231 (12)	N1—H1A	0.908 (10)
Fe—O5	2.1231 (12)	N1—H1B	0.905 (10)
O5—H5A	0.70 (3)	N1—H1C	0.906 (10)
O5—H5B	0.77 (3)	N1—H1D	0.908 (10)
S—O3	1.4538 (11)
O2^i—Fe—O2	180.0	Fe—O5—H5B	123.6 (18)
O2^i—Fe—O4^ii	90.99 (4)	H5A—O5—H5B	104 (3)
O2—Fe—O4^ii	89.01 (4)	O3—S—O2	109.79 (7)
O2^i—Fe—O4^iii	89.01 (4)	O3—S—O4	113.00 (6)
O2—Fe—O4^iii	90.99 (4)	O2—S—O4	110.38 (6)
O4^ii—Fe—O4^iii	180.00 (4)	O3—S—O1	109.01 (6)
O2^i—Fe—O5^i	88.35 (4)	O2—S—O1	109.67 (7)
O2—Fe—O5^i	91.66 (5)	O4—S—O1	104.86 (7)
O4^ii—Fe—O5^i	86.93 (4)	S—O2—Fe	132.53 (7)
O4^iii—Fe—O5^i	93.07 (4)	S—O4—Fe^iv	131.93 (6)
O2^i—Fe—O5	91.65 (4)	H1A—N1—H1B	117 (4)
O2—Fe—O5	88.34 (4)	H1A—N1—H1C	74 (4)
O4^ii—Fe—O5	93.07 (4)	H1B—N1—H1C	83 (4)
O4^iii—Fe—O5	86.93 (4)	H1A—N1—H1D	75 (4)
O5^i—Fe—O5	180.0	H1B—N1—H1D	54 (4)
Fe—O5—H5A	120 (2)	H1C—N1—H1D	102 (4)

Symmetry codes: (i) −x, −y, −z; (ii) x+1, y, z; (iii) −x−1, −y, −z; (iv) x−1, y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5A···O3^v	0.70 (3)	2.07 (3)	2.7262 (16)	155 (3)
O5—H5B···O2^vi	0.77 (3)	2.57 (3)	2.9967 (16)	117 (2)
O5—H5B···O3^vi	0.77 (3)	2.59 (3)	3.2335 (17)	143 (2)
N1—H1A···O3^vii	0.91 (1)	2.00 (1)	2.9007 (12)	175 (5)
N1—H1C···O1	0.91 (1)	2.19 (1)	3.0790 (12)	168 (4)
N1—H1D···O4^viii	0.91 (1)	1.95 (1)	2.8433 (12)	168 (5)

Symmetry codes: (v) −x−1, −y−1, −z; (vi) −x, −y−1, −z; (vii) −x−1, −y−1, −z−1; (viii) −x−1, −y, −z−1.